Trigger mechanism for automatic weapons



June 3, 1969 E X ET AL 3,447,525

TRIGGER MECHANISM FOR AUTOMATIC WEAPONS Filed April 21, 1966 J INVENTORSI JiFi CERMAK, Karel VYSTR CIL BY! Bohuslav NOVOTNY m 0. 5% Their Aflorney United States Patent US. Cl. 124-11 Claims ABSTRACT OF THE DISCLOSURE In a fire-arm wherein missiles or bullets are propelled out of the barrel of the fire-arm by means of a compressed gaseous medium, an improved trigger mechanism, which includes a biased trigger that is pivotally mounted in the body of the fire-arm. The trigger is T-shaped and has a pair of oppositely extending arms. A pair of levers respectively having oppositely extending arms are pivotally mounted in the body of the fire-arm on a common pivot support. A second lever of the pair of levers and the T- shaped trigger are biased in opposite directions. One arm of the first lever of the pair of levers is operatively connected to one arm of the T-shaped trigger so that when said trigger is manually pivoted in one direction, said first lever is pivoted in the opposite direction. One arm of the second lever and the other arm of the first lever are adapted to be selectively moved into and out of the path of a hammer which is reciprocally slidably mounted in the fire-arm thereby selectively releasing the hammer and retaining it in the firing position in the fire-arm.

This invention relates to a trigger mechanism particularly for fire-arms using compressed air or gas for the propulsion of the missile or bullet through a barrel of the fire-arm.

There exist at present a large number of trigger mechanisms for automatic weapons, but only a small number thereof can be applied to weapons using for propulsion of their missiles or bullets compressed air or gas. For sake of clarity the compressed air or gas will be called hereinbelow the compressed medium.

The known trigger mechanisms for weapons operating with a compressed medium require that the smallest possible amount of energy of the compressed medium is used for cocking the hammer so that the whole accumulated energy of the compressed medium is not substantially reduced. Thus, only that type of the trigger mechanism of automatic weapons is practical, which requires, in the course of shooting, only a negligible amount of energy within the interval between successive shots. This design criteria has heretofore been met in the prior art by providing a mechanism comprising a trigger and a pivotally arranged trigger lever cooperating with said trigger, whereby the trigger lever is provided on its end with a stable lug for engagement with an extension of the hammer. The trigger lever is provided in its central part with a spring loaded pivotable lug also designed for engagement with the hammer, however with another extension thereof. The distance of the working edges of the stable and pivotable lugs is smaller than the distance between the extensions of the hammer. By pressing the trigger, the trigger lever is pivoted, whereby the stable lug comes out of engagement with the extension of the hammer. The latter then undergoes, due to the action of a spring, a corresponding forward movement. In the course of the reverse movement of the hammer after the shot has been "ice fired, when the trigger remains depressed, the hammer passes over the pivotable lug beyond the working edge of the pivotable lug, which is pivoted due to the action of its spring and retains the hammer in the course of its following forward movement. When the trigger is released, the pivotable lug is pivoted and the hammer released, the hammer comes, however, subsequently to a stop when contacting the stable lug of the trigger lever.

This solution requires for the operation of the pivotable lug only a negligible amount of energy, but has also some drawbacks, which manifest themselves in a required complicated and, consequently, costly manufacturing process. Thus, in this known construction two extensions on the hammer must be provided, the distance between them being strictly limited by the distance between the edges of the stable and pivotable lug. The trigger lever proper is also difiicult to manufacture, because its pivotable lug requires, for its correct operation, tobe supported directly by the bolt of the trigger lever.

It is an object of this invention to remove the said drawbacks of the prior art, which is achieved by the provision of an additional retaining lever arranged pivotally on a common bolt with the main trigger lever, whereby one arm of this additional retaining lever is, due to spring pressure, mostly in contact with the second arm of a two arm lever, which is integral with the trigger, whereas the second arm of the retaining lever is provided with a catch for engagement with an extension of the hammer, whereby this second arm of the retaining lever is longer than the corresponding arm of the main trigger lever, and has one end designed to catch and engage with the extension of the hammer.

An advantage of the trigger mechanism according to this invention is its simple and unpretentious manufacture, which is particularly manifested by the constructional arrangement of the trigger lever and the retaining lever which are supported by a common bolt. This feature provides another advantage, namely that only a single extension is required on the hammer with which both levers cooperate.

An example of an embodiment of the object of this invention is shown in FIG. 1 of the drawing wherein there is illustrated an elevation of a pistol in a partly longitudinal section with the trigger mechanism illustrated partly in section.

The schematically shown pistol comprises a body 1 with a barrel firmly connected therewith and a handle portion 3 equally firmly fixed to the body 1. The usual mechanisms are located within the body 1 and within the handle portion 3. In particular there are arranged therein a not shown pressure vessel, valves, the cocking device, locks and, furthermore, the illustrated hammer 4 and the illustrated trigger mechanism. The trigger mechanism is composed of the trigger 5 arranged pivotable on the bolt 6, said bolt 6 being firmly fixed in the body 1. The trigger 5 is provided with a two arm lever 7 so that the whole forms a unit of the shape of the letter T. One arm of the two arm lever 7 is provided with a recess 8 into which one end of a compression spring 9 engages, which bears with its other end against the bottom 10 of the body 1. The second arm of the two arm lever 7 is provided with a bolt 11 arranged parallel with the supporting bolt 6 which engages into an elongated opening 12 on one arm of a pivotally supported trigger lever 13, the second arm of Which is provided with a catch 24 for engagement with the extension 14 of the hammer 4. The trigger lever 13 is pivotally supported by means of a bolt 15, which is fixedly mounted in the body 1 of the pistol. A retaining lever 16 is also pivotally supported by said bolt 15. One arm of the retaining lever 16 terminates in a catch 25 which is designed for engagement with the extension 14 of the hammer 4, whereas the second arm of retaining lever 16 is, due to the pressure exerted by a spring 17, predominantly in contact with that arm of the two arm lever 7, upon which the pressure spring 9 acts from the other side. Thus, a relationship exists between the pressure springs 9 and 17 in that the pressure spring 9 is designed to absorb a larger pressure than the Spring 17. The length of the arm of the retaining lever 16, provided with the catch 25, is slightly larger than the length of the corresponding arm of the trigger lever 13 with the catch 24.

The hammer is supported in sliding fashion in the pistol body 1 so that it engages with its piston extension 18, which is preferably of cylindrical shape into the hollow tubular space 19 which terminates at its opposite end at the not shown rear part of the barrel 2. The hammer 4 is biased in the direction towards the barrel 2, due to the pressure exerted by the spring 20, which bears one end against the bottom of the recess 21 in the hammer 4 and with the opposite end against a collar 22 fixed to a guiding rod 23, one end of which freely engages into the recess 21 and the opposite end projects into a mating bore of the pistol body 1.

When pressing the trigger 5, the two arm lever 7 is pivoted, which causes One of its arms to compress the pressure spring 9 whereas its other arm engages by means of its transmission bolt 11 with one arm of the trigger lever 13 thereby pivoting this trigger lever 13 about the pivot support 15 so that the second arm of the trigger lever 13 disengages With its catch 24 the extension 14 of the hammer 4. The hammer 4 is thereafter pushed by the spring towards the barrel 2 where it strikes in the course of the final phase of its forward movement a not shown valve, which allows the pressure medium, for instance pressured gas, to enter by way of not shown channels the hollow space 19 whereby the pressure medium proceeds therefrom into the not shown bore of the barrel 2 causing the not shown missile or bullet to be shot out of the barrel 2. When pressing the trigger 5, one arm of the retaining lever 16 follows due to the action of pring 17 the pivoting movement of one arm of the two arm lever 7 of the trigger 5, whereby the other arm of the retaining lever 16 comes in contact with the hammer 4 against which it is pressed due to the action of the spring 17. In the course of shooting the weapon, when the pressure medium enters the hollow space 19, there occurs due to the pressure of the pressure medium in addition to the action upon the not shown missile, an action upon the piston extension 18 of the hammer 4. Thus, the hammer 4 performs a quick rear movement, in the course of which it compresses the spring 20. Simultaneously therewith the hammer 4 slides along the top portion of the rear leg of the retaining lever 16.

As soon as the hammer 4 passes with its extension 14 the position of the catch of the retaining lever 16, this lever 16 is moved due to the action of spring 17, into a position of engagement with the extension 14 of the hammer 4. After the rearward movement of the hammer 4 has been finished, the hammer 4 is again pushed by the spring 20 towards the barrel 2, it strikes however on its forward track with its extension 14 the catch 25 of the retaining lever 16, so that its further forward movement is prevented. After release the trigger 5 returns, due to the action of the pressure spring 9, into its rest position. In the course of this movement the auxiliary two arm lever 16 is also pivoted by the action of the spring 9 and against the pressure action of spring 17 until it comes out of engagement with the extension 14 of the hammer 4. Simultaneously with the pivoting of the retaining lever 16 a pivoting movement of the trigger lever 13 in the opposite direction takes place whereby the trigger lever 13 with its catch enters into the path of the extension of the hammer 4 which, after release from the retaining lever 16, performs a small forward movement along the track equal to the difference of lengths between the arms of the retaining lever 16 and the trigger lever 13, which .4 are respectively catches 24 and 25. The hammer 4 then strikes with its extension 14 against the catch 24 of the trigger lever 13. The hammer 4 is thus again ready to perform a forward movement after the trigger 5 has been pressed.

The trigger mechanism according to this invention can be utilized in all automatic weapons having a compressed medium for propulsion of the missiles. The operation of the trigger mechanism of this invention produces low losses of energy within the interval between successive shots.

Although our invention has been illustrated and described with reference to one preferred embodiment thereof, we wish to have it understood that it is in no way limited to the details of said embodiment but is capable of numerous modifications within the scope of the appended claims.

What we claim is:

1. In a weapon of the character described, wherein missiles, bullets or the like are propelled out of a barrel of said weapon by means of a compressed gaseous medium being stored in a pressure vessel having release valve means,

an improved trigger mechanism, comprising in combination,

a hammer member slidably reciprocally mounted in said weapon, said hammer member being biased towards said barrel;

a biased trigger pivotally mounted in said weapon about a first axis, said trigger having a pair of members projecting in opposite directions from said first axis; first lever pivotally mounted in said weapon about a second axis, said first lever having two oppositely extending arms, said first and second axes being parallel with respect to each other, one member of said pair of members of said trigger and one arm of said first lever being operatively connected to each other so that when said trigger is manually pivoted in one direction, said first lever is pivoted in the opposite direction;

a second lever pivotally mounted in said weapon about said second axis and being biased against said trigger, said second lever and said trigger being biased in opposite directions, said second lever also having two oppositely extending arms, one arm of said second lever and the other arm of said first lever being adapted to be selectively moved into and out of the path of said hammer member, said one arm of said second lever being longer than said other arm of said first lever.

2. In a weapon of the character described, the improved trigger mechanism as set forth in claim 1, wherein said trigger is T-shaped, said one member of said T-shaped trigger which is operatively connected to said one arm of said first lever includes a projecting rod and said one arm of said first lever includes an elongated slot, said projecting rod being disposed in said elongated slot.

3. In a weapon of the character described, the improved trigger mechanism as set forth in claim 2, including a first spring mounted in said weapon, said first spring bearing against said hammer member with one of its ends and against the bod of said weapon with the other one of its ends, thereby urging said hammer member towards said barrel.

4. In a weapon of the character described, the improved trigger mechanism as set forth in claim 3, including a second spring mounted in said weapon between said other member of said T-shaped trigger and the body of said weapon, said second spring pivoting said other member of said T-shaped trigger towards the other arm of said second lever.

5. In a weapon of the character described, the improved trigger mechanism as set forth in claim 4, including a third spring mounted between said other arm of said second lever and the body of said weapon, said third spring pivoting said second lever towards said T-shaped trigger, said second spring being stronger than said third spring; whereby, when said T-shaped trigger is manually pivoted against the action of said second spring, said first lever is pivoted in the opposite direction and said other arm thereof moves out of the path of said hammer member which then moves towards said barrel and thereby actuates a release valve means which causes said compressed gaseous medium to be released from a pressure vessel and enter said barrel and said released gaseous medium also urges said hammer member away from said barrel against the action of said first spring, said one arm of said biased second lever being urged by said third spring into the path of said hammer member as soon as the latter has passed a predetermined point during its return stroke, so that said hammer member is prevented by said one arm of said second lever from being again moved forward by said first spring after the pressure exerted on said hammer References Cited UNITED STATES PATENTS 8/1962 Kline et al 12411 XR 9/1965 Shepherd 124-11 RICHARD C. PINKHAM, Primary Examiner. W. R. BROWNE, Assistant Examiner.

US. Cl. X.R. 12437 

